Free-floating street sweeper elevator



Aug. 30, 19 H. BURGDORFF FREE-FLOATING STREET SWEEPER ELEVATOR 3Sheets-Sheet 1 Filed June 7, 1956 y KW Mi m0 MM ND #7 m6 r mm A 5 W a Y8g I \MMJJ w D EN N NE 1950 H. BURGDORFF 2,950,827

FREE-FLQATING STREET SWEEPER ELEVATOR Filed June 7, 1956 3 Sheets-Sheet2 I N V EN TOR. A LWA? Y 5 0,9617 OKFF .4rraeMsys.

Aug. 30, 1960 H. BURGDORFF FREE-FLOATING STREET SWEEPER ELEVATOR FiledJune 7. 1956 (n m (n m (n m (n III/III!!! 3 Sheets-Sheet 3 IIIIII/III/zINVENTOR. HEMP) .EURGDOEFF BY FREE-FLOATEN G STREET SWEEPER ELEVATORHenry Burgdorif, 127 W. 65th St., Long Beach, Calif.

Filed June 7, 1956, Ser. No. 590,013 2 Claims. ((1214-17) This inventionrelates generally to a truck-type street sweeper having a motor drivenpick-up brush and refuse hopper, and an elevator means for transportingrefuse from said brush to said hopper through a refuse chute. Moreparticularly, this invention relates to an elevator means floatingfreely in the street sweeper body and supported on a transverse axisintermediate the pick-up and discharge ends of said elevator means. inthe preferred form of the invention, the elevator is supported onindependent pivot supports at each side, said supports being movable inslots normal to said chute to permit said elevator to move away fromsaid chute, and to roll and pitch thereon as refuse objects aretransported between said elevator and said chute.

This application is a continuation-in-part of my copending application,Serial No. 570,293, filed March 8, 1956, now Patent No. 2,917,761, on aStreet Sweeper Hopper and Lift Mechanism.

Almost all truck-type street sweepers presently in use pick up dirt fromthe street by means of a large cylindrical broom mounted on an axistransverse to the truck, and driven through power connections with thetruck engine in a direction of rotation counter to the relative movementof the street surface when the truck is in forward motion. The broom issupported with the bristle tips barely in contact with the streetsurface so that its rotation whisks refuse matter forward and upwardinto an upwardly sloping chute. An elevator means of the conveyor belttype is used to carry refuse upwardly through the chute to a dischargepoint at its upper end, at which the refuse falls into a hopper. Suchstreet sweepers are also usually provided with a gutter broom on theright side, water spray means, means for lifting the brooms duringnon-sweeping travel, and hopper dumping means.

The present invention is concerned with the elevator means, and itsco-action with the brush, chute, and hopper. In street sweepersheretofore known, the elevator means has frequently been damaged orbroken down by the engagement of rocks, boards, or other bulky refuseobjects between its moving surfaces and the chute. The bristles of thepick-up broom are large enough, strong enough, and driven with enoughpower is pick up relatively large objects and throw them into the intakeend of the chute, where transverse bars on the moving belts or chainsengage them and scrape them upwardly through the chute to the dischargeend at which they are dumped into the hopper. Frequently, a refuseobject which has greater thickness than the space between the surface ofthe chute and the moving chains jambs in the chute, bending or breakingthe chute, the chains, or the driving mechanism, before the power can beshut off.

Various means have been devised for increasing the ability of theelevator to pass large objects up through the chute without a high rateof destructive break downs. In devising such means, however, it has beennecessary to insure that the scraping surfaces of the elevator remainnear to or in contact with the chute surface during nor- Patented Aug.so, 1960 mal operation, so that the elevator would be capable ofefiiciently transporting dirt, leaves, papers, and small objeets, whichcomprise most of the refuse picked up. For example, most street sweeperelevators use moving transverse bars with rubber flap edges, usuallyreferred to as squeegee bars, which are capable of lifting small refuseor of yielding to bulky objects. The effectiveness of this arrangementis limited to small stones and the like.

Another method of protecting the elevator has been to hang it inswinging support from the upper shaft of the conveyor system. Thisarrangement left the lower end of the elevator free to swing away fromthe chute when large objects were engaged at the pick-up end. However,the tolerance of such elevators diminishes toward the upper end, andsometimes, a large object, after starting up the chute, jambs in itsupper part. Some alleviation of these difiiculties has been accomplishedby carrying the transverse squeegee bars on relatively loose andunsupported flexible chains between upper and lower pulleys orsprockets; this. design suffers from the disadvantage of excessive chainwear and breakage.

Previous swinging or pivotally supported street sweeper elevators sufferfrom the disadvantage that they tend to drop a large amount of refuseload all the way back to the street whenever a bulky object is movingthrough the elevator. The lower part of the elevator remains displaced avery substantial distance away from the chute surface as the bulkyobject progresses through the upper part of the chute. Indeed, thedisplacement of the lower end of the elevator may be several times thethickness. of the object itself. In most previous designs, the presenceof a bulky object at one side of the elevator displaces the elevator, ifit is displaceable at all equally across its entire width.

Of the many other disadvantages of previous designs, probably the mostserious is the difficulty of repair of the elevator. In most previousdesigns, it has been necessary to remove substantial parts of thesweeper body, and to dismantle the elevator and its driving mechanism inorder to replace its. broken parts.

It is a primary object of the present invention to provide a streetsweeper pick-up assembly in which the elevator and its driving meanscomprise a unitary assembly supported in a free-floating manner withinsaid chute, being displaceable away from the chute surface at either endor throughout its length.

Another object, incidental to the foregoing, is to provide an elevatormeans capable of displacement away from the chute surface at eitherside, or both sides, to prevent any rocking motion best suited toaccommodate the load engaged at the moment.

Another major object of the present invention is to provide an elevatormeans, which, together with its driving means, can be readily removedfrom its mounting for repair, without disassembly of other parts of thestreet sweeper.

Another object of the invention is to provide a street sweeper elevatorin which the conveyor chains are supported over their entire path inprotecting channels The foregoing and other objects, and the manner inwhich they are attained will be clearly apparent from the followingdescription of an illustrative specific embodiment, which is illustratedin' the accompanying drawings, in which:

Figure 1 is a right side view of a street sweeper including thecombination of the present invention with associated street sweepercomponents;

Figure 2 is a fragmentary left side View showing the elevator drivingmeans;

Figure 3 is a longitudinal vertical sectional view through the rear partof the street sweeper of Figure 1, showing the elevator in its normaloperating position;

Figure 4 is a fragmentary view similar to Figure 3, but showing theoperation of the elevator when it is transporting a bulky refuse object;

Figure 5 is a sectional view of a longitudinal section through theelevator, taken as indicated by the arrows 5-5 in Figure 3;

Figure 6 is an enlarged side view of the elevator assemy;

Figure 7 is a plan view of the elevator assembly with the centralportion broken away to reduce the relative width of the drawing; and

Figure 8 is a fragmentary part of a transverse sectional view taken inthe direction of the arrows 86 in Figure 6.

In Figure l a street sweeper, indicated generally by the numeral 19, isseen to be comprised principally of a four-wheel truck chassis 11carrying a drivers cab 12 and engine section 13 in the for-ward part,and a street sweeper assembly 14 in the rear part.

The street sweeper assembly 14 includes a sweeper body 15, which housesa refuse hopper and a water tank, not seen in this view.

A disc shaped gutter broom 16 is provided at the right side of thestreet sweeper it) to whisk refuse from the side of the truck to thearea between the truck wheels 17 under the truck chassis ll. Acylindrical pick-up broom l8, transversely disposed at the rear of thestreet sweeper is driven by means to be disclosed hereinafter in thedirection of the arrow l9 to whisk refuse in the path of the streetsweeper ltl forwardly and upwardly into the intake end 26 of an upwardlysloping chute 21.

A conveyor belt type of elevator 22, seen in dashed line outline inFigure 1, and in sectional view in Figure 3, is used to push refusethrough the chute 21 to its upper or discharge end 23, where the refusefalls into a hopper 2e inside of the sweeper body 15.

As set forth in detail in my co-pending application Serial No. 570,293,the gutter broom 16 is mounted on a vertically swinging arm assembly 25,pivoted at 26, supported with sector hinge 27, and by a swinging rollersupport 28 pivoted at 29. The swinging roller support 28 is yieldablysustained by a spring 30, which terminates on a nut 31 carried on anadjusting screw 32. The gutter broom is driven by hydraulic motor 33which rides freely on the swinging arm 25, and is supplied withhydraulic fluid under pressure through lines 34.

The pick-up broom 19 rotates on a shaft 35, each end of which is carriedon an independent vertically swinging arm 36 to provide a knee actionoperation which allows the broom 18 to adjust to the contour of the roadsurface, in a manner described in detail in my co-pending application,Serial No. 570,293.

The pick-up broom arm 36 is pivoted at 37 and yield ably carried onspring 38, which is adjustable at its lower end by nut 39 and adjustmentscrew 49.

When it is desired to move the street sweeper 19 with the pick-up broom18 in non-sweeping position, the broom 18 and its associated parts, suchas the arm 36 and the side shoe 41, can be retracted from the roadsurface by retraction of the hydraulic cylinder 42, pivoted link 43, andchains 44.

A second hydraulic cylinder 45 may be employed to push the pick-up brooml8, and its associated parts, out of the way for dumping, whilesimultaneously unlatching a refuse hopper latch 46, and swinging open arefuse hopper gate 47 by means of pull rod 48.

Figure 2 reveals the left side of the portion of the street sweeperassembly in which the elevator 22 is mounted. A portion of the elevator22 is visible through an opening 49 in the side of the street sweeperchute 29.

A reversible hydraulic motor 50 is carried on the elevator 22 andcomprises a part of its assembly, being 4 mounted on a drive shaft 51 atits left end 52 external to the chute 21. Hydraulic motor is driven bymeans of hydraulic fluid supplied through hydraulic lines 53.

It is a unique and advantageous feature of the present invention thatthe elevator can be removed as a unit from the sweeper body by merelydetaching the hydraulic motor 50 from the shaft end 52 and removingeight fastening bolts 54, four on each side of the chute 22. As seen inFigure 5, the bolts 54 fasten the rectangular flange bases 55 and S6 ofleft and right supporting pins 57 and 58 respectively.

The supporting pins 57 and 58 pass through holes 59 and 60 in the sidewalls 61 and 62 of the chute 21, and project inwardly, in alignment witheach other, through slots 63 and 64 in left and right side panels 65 and66 respectively of the elevator 22.

It is a preferred feature of the present invention to locate the axes ofsupporting pins 57 and 53 very near the center of gravity of theelevator 22. It is then found that the elevator rides normally withsubstantially uniform light bearing on the bottom surface 67 of thechute 22. When a large refuse object, such as a rock 68 illustrated inFigure 4, is thrown into the chute 22 by the pick-up broom 18, the pinsupport permits the entire elevator assembly 22 to be displaced awayfrom the chute bottom surface 67. The elevator assembly 22 is thus freeto be litfed, or to roll laterally or to pitch fore and aft as refuseobjects of different shapes and sizes are transported.

Figures 6, 7, and 8 show the present specific embodiment of theinvention in enlarged detail. The right and left side panels 65 and 66are bolted by bolts 69 to the flanged ends 79 of rigid cross members 71and 72 to form a rigid frame structure for the entire elevator '22.

The drive shaft 51 is journaled in bearings 73 and 74, which are boltedto bearing brackets 75 and 76, which are welded to the left sides ofside panels 65 and 66 respectively.

The shaft 51 carries a pair of sprockets 77 and 78, supported inalignment with the upper ends of the side panels 65 and 66, and keyed asat 79 to rotate with the rotation of shaft 51.

At the lower or pick-up end of the elevator 22, a pair of rotatablesheaves or pulleys 8t and 81 are similarly supported in alignment withthe left and right side panels 65 and 66 respectively on pulley brackets82 (Figure 6) and 83 (Figure 3).

The pulley brackets 82 and 83 are adjustable longitudinally relative totheir supporting side panels 65 and 66 since each is bolted to its sidepanel by means of bolts 84 received in slots 35 in the side panel. Eachof the pulleys 8t) and 81 is held in adjustment against the forcesexperienced during use by means of its own adjusting screw 86 and 87respectively, threaded through brackets 88 and 39 on the inner sides ofthe side panels 65 and 66 respectively, and bearing on the upturned ends90 and 91 of the pulley brackets 82 and 83.

The left and right sides of the elevator 22 are each provided with aflexible link chain loop 92 and 93, respectively, mounted to ride on thesprockets 77, 78 and the pulleys S0 and 81, when driven by rotation ofthe shaft 51.

It is an important and advantageous feature of the present inventionthat the chains 92 and 93 are supported throughout their length betweenthe pick-up and discharge ends of the elevator 22, and in bothdirections of travel by protective channels 94 welded on the upper andlower edges of each of the side panels 65 and 66.

The chains 92 and 93 carry a number of transverse squeegee bars 95,spaced at regular intervals around the entire conveyor loop. Each of thesqueegee bars 95 consists of a piece of angle iron 96 welded to thechains 92 and 93 at each end, and provided with a stiff rubber flap 97bolted to the back of the L 96 by means of a flap plate 98 and bolts 99.If desired, lubricant may be applied to each of the chains 92 and 93 bymeans of a grease cup 100.

It will be seen that the elevator 22, although in coacting combinationwith the pick-up brush 18, the chute 21, and the refuse hopper 24, is anentirely independent assembly, being free to move away from the bottomsurface 67 of the chute 21, and to pitch and roll thereon. The elevator22 is not permitted to yaw, however, or to move longitudinally withrespect to the chute 21, being restricted in its freedom of movement bythe engagement of the supporting pins 57 and 58 with the slots 63 and64. The entire elevator is free to make a slight lateral shifting, ifstress is experienced during operation required to do so, since pins 57and 58, and the width of the chute 21 permit some lateral play. Also, itwill be noted that gravity urges the elevator 22 into the normalposition illustrated in Figure 3. Even in this position, however, theelevator 22 does not bear heavily upon the bottom surface 67 of thechute 21, since the pins 57 and 58 bear upon the upper ends of the slots63 and 64 in the normal operating position. Preferably, the upper edgesof the slots 63 and 64 are provided with a bearing surface of increasedthickness as indicated at 101 and 102 in Figure 5.

It will also be appreciated that the provision of an adjustable androtating member at the lower end of each side panel, such as areprovided here by the pulley brackets 82 and 83 and the pulleys 80 and81, are mere ly refinements, since the chains 92 and 93 could be made toslide around the lower ends of the side panels 65 and 66 in stationary Uchannels, although the frictional Wear would be considerably increasedthereby.

It will be appreciated that I have described the foregoing specificembodiment as illustrative of my invention only, and it is not myintention to restrict the scope of the invention to the specific detailsor particular arrangements described, but intend the scope of myinvention to cover all forms falling within the limits defined by thefollowing claims.

I claim:

1. In a street sweeper, a refuse hopper, an upwardly inclined chuteextending to said hopper, and elevator means for transporting refuse tosaid hopper along the surface of said chute, said elevator meanscomprising: an elevator frame extending longitudinally from a lowerpick-up end to an upper discharge end near said hopper, and includingtwo side panels disposed substantially parallel to said chute; aflexible conveyor means associated with each of said side panels;transverse members supported at each end by one of said conveyor meansto move refuse through said chute; motor means mounted on said elevatorframe for driving said conveyor means; a single slotted track means ineach of said side panels and disposed in a plane substantially normal tosaid chute and approximately centered between said pick-up and dischargeends thereof; and pin means at each side of said chute engaging saidslotted track means to support said elevator side panels.

2. In a street sweeper, a refuse hopper, an upwardly inclined chuteextending to said hopper, and elevator means for transporting refuse tosaid hopper along the surface of said chute, said elevator meanscomprising: an elevator frame disposed substantially parallel to saidchute and including a pair of of side panels, each of said panels havinga single slot normal to said chute and near the center thereoflongitudinally adjustable lower end members on each of said side panels;a guide channel on the upper and lower edges of each of said sidepanels; a sprocket rotatably mounted at the upper end of each of saidside panels and in alignment therewith; a loop of flexible chain aroundeach of said side panels and supported in said supporting channels anddriven by said sprockets; transverse scraper members supported at eachend on said flexible chains; motor means mounted in said elevator frameto drive said sprockets; and a pin means at each side of said chuteengaging said slot to support said elevator means while yielding topitching and rolling movements thereof.

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